Recent technological investigations in the field of silver halide color photographic materials largely concern development of photographic materials having high photographic speed, as represented by photograph-taking films of ISO 1600, which photographic materials can provide satisfactory graininess, sharpness and color reproducibility even when used for picture taking with a camera of small format, such as a 110-size system or disk-size system, or which film is fitted with a lens, such as "Utsurundesu Hi" or "Utsurundesu Panoramic", trade name, products of Fuji Photo Film Co., Ltd. Namely, there is a demand for a much higher level of individual photographic characteristics.
In response to these demands, the use of tabular grains has been investigated to provide improvements in sensitivity, including enhancement of color sensitization efficiency by the use of sensitizing dyes, sensitivity-granularity relationship, sharpness and covering power as disclosed in U.S. Pat. Nos. 4,434,225, 4,414,310, 4,433,048, 4,414,306 and 4,459,353, JP-A-58-113927, JP-A-59-119350, etc. (The term "JP-A" as used herein means an "unexamined published Japanese patent application").
Furthermore, methods of using tabular grains having relatively small sizes (diameter of grains: 0.6 .mu.m or less) are disclosed in U.S. Pat. Nos. 4,439,520, 4,435,499 and 4,748,106, JP-A-62-99751, etc.
Tabular grains described in those specifications have an average aspect ratio of 5 or more, or 8 or more. The use of such tabular grains is effective in reducing the light scattering phenomenon caused by silver halide grains in the emulsion layers of a sensitive material, which phenomenon is considered mainly responsible for deterioration of sharpness. However, grains having a high aspect ratio are often inferior in stress resistance, such that it was difficult to increase sharpness to a satisfactory extent without deterioration of stress resistance.
In addition, since tabular grains having a high aspect ratio are fine and extremely thin, such grains tend to become deformed, for example, by perforating, under influence of the pAg of the emulsion containing these grains, and by being subjected to reagents which dissolve silver halides, etc. Therefore, it has hitherto been difficult to stably produce a silver halide photographic material containing such a tabular emulsion.